The present invention relates to a magnetic recording medium obtained by forming a magnetic layer comprising a mixture of magnetic-metal corpuscles and their oxide on a nonmagnetic substrate, a fabrication method of the medium, and a read-write machine using the medium, and in particular to a magnetic recording medium suitable for a perpendicular magnetic recording medium having excellent magnetic characteristics, a fabrication method of the medium and a read-write machine using the medium.
In recent years, the recording density in the field of magnetic recording has been significantly increased. In particular, the perpendicular magnetic recording method has a feature that self-demagnetization is decreased as the recording density is increased unlike the longitudinal magnetic recording method. The perpendicular magnetic recording method thus attracts public attention and is now being studied energetically.
With regard to perpendicular magnetic recording media, characteristics of Co-Cr alloys are discussed by S. Iwasaki and K. Ouchi in IEEE Trans., Magn., MAG-14, p. 849 (1978),for example. Co-Cr alloys are large in both magnetic anisotropy and saturation magnetization and have excellent characteristics as perpendicular magnetic recording media. However, Co-Cr alloys have a problem that they tend to be worn away because they are metals. In view of this, Co-CoO evaporated films comprising a mixture of Co and its oxide are studied and perpendicular magnetic films having large magnetic anisotropy are obtained as described in JP-A-59-140629, for example. Further, perpendicular magnetic recording media using partially oxidized Fe-Co films are also now studied vigorously as described in Journal of the Japan Society of Applied Magnetics, Vol. 11, No. 2, 1987, p. 61.